Mike, the rotor sits on top of the c-adv shaft. Just put the rotor on and give a twist, it should rotate just over 15* and spring back smoothly. If not some lubrication/cleaning may be in store for you. You can drop a bit of oil into the shaft housing when the rotor is removed, yep right down the hole. Won't lube the weights but can easily free up the shaft/counter-shaft assembly.
Not as tough as it sounds.
Dave Neptune